This invention relates to a method for the cleansing and care of the teeth and gums, comprising the step of conveying a liquid to and discharging it from an outlet orifice, and to a jet nozzle for a device for the cleansing and care of the teeth and gums, particularly for a handpiece of an oral irrigator, with a nozzle head in which a feed line runs which opens into an outlet orifice from which a liquid can emerge.
A method of this type and a jet nozzle of this type are known from European Patent No. EP 0 175 881 B2. This patent contains a description of an electrically powered oral irrigator for oral and dental hygiene, which includes a handpiece to which a jet nozzle is attachable. The jet nozzle is equipped with a nozzle head in which a feed line runs from an inlet, which is connected to the handpiece, to an outlet. When the oral irrigator is switched on, water is pumped via the handpiece to the jet nozzle and hence to the nozzle head. Here the water emerges in the form of a single jet from the outlet. This single jet can be employed by the user to care for and cleanse his teeth and gums. The single jet is suitable in particular for clearing food particles or the like from the subcrestal pockets between the teeth and the gums.
It is known furthermore that inflammations of the gums such as gingivitis or periodontitis are caused by bacteria. The bacteria involved are mainly anaerobic bacteria which settle in the subcrestal pockets in particular. A distinction is made between facultative anaerobic bacteria such as actinobacillus actinomycetemcomitans, which can live in an atmosphere of air, and strict anaerobic bacteria such as porphyromonas gingivalis, which can survive only in the absence of oxygen.
Experience has shown that in both cases a supply of oxygen can permanently disturb or even end particularly the growth of the bacteria. This can result ultimately in the death of the bacteria and hence in the treatment and cure of inflamed gums.
For this to happen it is necessary to confront the bacteria with as much oxygen as possible. This means that as much oxygen as possible has to be conveyed as deeply as possible into the subcrestal pockets in order to be able to disturb the bacteria there in their growth.
Ordinary tap water has an oxygen content of about 40% up to about 80% saturation, corresponding to about 3-8 mg/l oxygen in the temperature range from 20.degree. C. to 40.degree. C. This has been discovered to be too little oxygen for the successful treatment and cure of inflamed gums.
It is also possible to add air to the water by having the pump draw in not only the liquid but also air, for example, and conveying it to the outlet. In this case, however, it has been discovered that because of the great difference in the density of water and air the two substances separate again very quickly so that the air escapes again. The air and hence the oxygen thus fails to get into the subcrestal pockets and is unable therefore to contribute to the treatment or cure of inflamed gums.
A further possibility is to blow gaseous oxygen directly into the subcrestal pockets. However, this involves the risk of embolism for the user, meaning that the pressure permitted is so very low as to be incapable of clearing food particles and the like from the subcrestal pockets.
With all the options described above it has been impossible so far to successfully combine the cleansing and flushing effect of water with the curative effect of oxygen.